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09/27/2006
Rainbows and Pineapple
Last week, I wrote of unknown contaminant(s) in the waters in
the Potomac watershed and of a visit by a purveyor of water
purification systems. Primed for water-related topics, I found in
the September Scientific American an article by Mark Fischetti
on water towers. The article had a picture of a decorative water
tower in Honolulu that I assume was the famed Dole “pineapple”
water tower. Coincidentally, shortly after reading the article, I
got an e-mail from my friend Dan in Honolulu. Although not
employed by Dole, Dan was once in pineapple with Libby and he
had a water-related query.
Dan was reading a book by Fannie Flagg in which a character
steps into a rainbow, experiencing a wonderland of color. Dan
questioned whether it was possible to step into a rainbow. He
often poses such deep and thought provoking questions.
Truthfully, I had never thought about this possibility nor was I
familiar with Ms. Flagg, a well-known author. Her book
“Standing in the Rainbow” was the one that Dan was reading.
Some years ago I had a golden opportunity to find the answer to
Dan’s question and even mentioned the experience in my
column. I was in a hotel in Pittsburgh and looked out the
window to see a beautiful rainbow touching down on the ground
a short distance away. I had never seen the end of a rainbow
touching the ground before but, not seeing a pot there, I didn’t
think to dash out and try to stand in it. Now, thinking about
Dan’s question, I had a feeling that Flagg had taken literary
license in describing the rainbow experience but I couldn’t pin
down a crisp reason why.
Then I went golfing with a former colleague at Bell Labs who
has a degree from Johns Hopkins and a PhD from Princeton.
Surely, with that background, he could answer the question with
authority. He assured me that I could never stand in a rainbow
and that as I approached the rainbow it would back away from
me. I will never be able to find the pot of gold at a rainbow’s
end. Further investigation of rainbows on the Web and in my
1962 World Book Encyclopedia supported his assertion. A
rainbow is an ephemeral thing. If you and I are looking at a
rainbow, we’re not even seeing the same rainbow. I conclude
that, like beauty, a rainbow is in the eyes of the beholder. A
rainbow is not in a particular location in the sky.
A rainbow occurs when the Sun is behind you and the light from
the Sun hits drops of water. Let’s take a single drop. When the
sunlight hits the round drop, some of the light is reflected and
some light enters the drop. The light entering the drop is bent at
an angle and hits the back of the drop, where some of the light is
reflected back through the drop. As it exits the drop, the light is
bent again and heads out towards your eye. This bending is
called refraction. Light of different colors gets bent or refracted
at different angles. Since sunlight consists of all the colors of the
rainbow (and more), a raindrop acts like a prism separating the
different colors. Put a lot of raindrops out there covering part of
the sky and all those drops refracting and reflecting the sunlight
give you a rainbow. Because the rainbow you see depends on
the angles of the light rays from the raindrops, the person
standing next to you sees rays of light from different angles and
therefore sees a slightly different rainbow.
So much for rainbows. Let’s go back to that Dole “pineapple”
water tower, which I vaguely recall seeing on one of our early
trips to Hawaii. I was disappointed to find that this huge
pineapple is gone, like the pineapple industry itself in Hawaii. I
feel an attachment to the structure inasmuch as we both appeared
on the scene in the same year, 1927. According to an article by
Burl Burlingame in the July 29, 2001 Honolulu Star-Bulletin, the
100,000 gallon pineapple water tower stood as a famed Honolulu
landmark at the Dole cannery for more than 60 years. The
pineapple tower was torn down in 1993 and the cannery is now a
mall.
I believe most of the Hawaiian pineapple business went to the
Philippines but I’ll never forget how delicious the pineapple,
fresh from the field, tasted on our first visit to Hawaii 40 years
ago. With the demise of the pineapple tower, the world’s largest
catsup bottle in Collinsville, Illinois is a prime contender for the
best-known decorative water tower. This tower was built in
1907 to serve the Brooks Foods catsup plant, also no longer in
business, but the catsup bottle tower has been preserved and
restored. My friend Dan told me today that there were plans to
rebuild the pineapple tower but nothing materialized.
The 100,000-gallon pineapple tower was actually small
compared to other towers that contain a million gallons of water
weighing over 8 million pounds. Why do we need these water
towers? After your city or town water emerges from the
treatment plant where it gets filtered and purified, it goes to a
pump house. There it gets pumped into a water line with a T-
valve that directs the water into the main water pipe or up into a
water tower (or towers). The water tower serves to keep the flow
and pressure of the water steady as the customer demands rise
and fall. Although the pumps alone can push the water through
the system, when everyone gets up to take a shower or starts their
laundry the demand is so high that, without water from the tower,
the pressure would fall and only a trickle would emerge from
some spigots.
Typically, a water tower holds a day’s supply of water or more
and draws down during the day when demand is high, with
refilling taking place at night. To supply the water at sufficient
pressure, the towers are typically a hundred feet or so above the
highest structures needing water. While the towers are quite
visible in flat areas of the countryside, you may not notice them
perched on top of city buildings and skyscrapers, which
generally have their own pumps and pressure regulating valves.
The structural demands on water towers containing 8 million
pounds of water can be quite daunting, depending on the type of
soil or rock upon which the tower sits. The Scientific American
article cites a situation in North Dakota where steel pilings have
to be driven 100 feet into the ground to support the tower, which
itself is a hundred feet above the ground. The towers also must
have exhaust fans, vents and maintenance manholes to permit
cleaning and sterilization of the tank periodically. The tower
structure must also be designed to withstand hundred-mile-an-
hour winds.
It seems a shame that our water companies go to all that trouble
to supply us with good water, only to have us opt for those
ubiquitous plastic bottles of water, some of which comes from
public water supplies just like our own!
Allen F. Bortrum
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